Monitoring engine parameters and performance has always been one of the primary functions of a pilot of an aircraft. Indeed, the instruments displaying the engine parameters and performance are included as part of the instrument scan expected of pilots. In most turboprop or turbofan-powered airplanes, there can be six or more different engine instruments to be monitored. Enabling a pilot to quickly and efficiently scan and interpret these instruments is one of the major objectives for a flight deck designer or an instrument manufacturer.
FIG. 1 depicts a known type of analog instrument 10 that uses a pointer or needle 12 to indicate engine parameter values. The analog instrument may be an actual instrument, or as shown in FIG. 1 may be a “virtual” analog instrument digitally created from measured engine parameters. A principal advantage of an analog instrument is that the position of needle 12 can easily be interpreted, even during a rapid scan of the instruments. Because precise values cannot be easily read from analog scales, however, a scrolling numerical value 14 may be provided.
It may be possible to arrange the orientation of all the engine instruments such that, during a predetermined flight condition such as engine idle or cruising speed, the needles of all the analog instruments 10 are pointed in the same direction. This makes a quick check of overall engine performance very easy, even though all instruments have to be scanned in order. However, such an orientation is valid for only one flight condition. Once such flight condition changes, such as during take-off or approach, the needles will not be aligned in the same direction.
FIG. 2 shows variations of another known type of instrument called tape instruments 16. Tape instruments 16 provide a scalar graphic representation of a value of an engine parameter. Some tape instruments 16a include pointers 17 that move along an edge of a numbered and scaled ‘tape’ 18 to indicate parameter values. A numeric display 20 may also be included to provide additional display accuracy. Other tape instruments 16b do not simulate a scrolling effect and do not include numeric displays. Such instruments merely depict parameter values 22 relative to acceptable maxima 24 and minima 26. Although tape instruments may be superior to analog instruments 10 because of the potential to display more possible parameter values, it usually is not as easy to design the scaling of the different tape instruments such that all the parameter values line up on the tapes at a predetermined flight condition.
FIG. 3 shows a digital readout 28, which is another known method of displaying engine parameters. Digital readout 28 is useful for setting and reading exact parameter values. However, because each of the values must be read and interpreted before the overall condition of the engines can be comprehended, digital readouts are almost impossible to interpret during a rapid instrument scan. What is needed is a method of displaying engine parameters such that an operator accurately comprehends engine condition during a rapid instrument scan.
It is therefore an object of the invention to provide a display of parameters that can be easily read and interpreted during a rapid scan of the display.
It is another object of the invention to provide a display of parameters that incorporates the graphical advantages of analog and tape instruments.
It is yet another object of the invention to provide such a display to indicate values of aircraft engine parameters.
A feature of the invention is the combination of multiple parameters to create a two-dimensional geometric shape whose form is representative of the values of the parameters.
An advantage of the invention is that multiple parameters may be read and comprehended by referring to a single instrument or display.